KVAR RATING CALCULATOR,CAPACITOR BANK SIZE CALCULATION

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  Determination of Required Capacitor Rating by measurement 3 Methods are used. 1. Measurement with current and power factor 2.Measurement with recording of Active and Reactive power. 3.Measurement by Reading Meters . 1 . Measurement with Current and power factor The active power P is calculate from the measured voltage V ,apparent current Is and Power Factor P=√3*Voltage*apparent Current*cosψ *10^-3 If the desired power factor cosψ has been specified, the capacitor power rating can be calculate from the following formula: Qc = P. (tan ψactual - tanψ desired) Let's See the Example Measured Apparent Current Is : 248 Amps Power Factor cos ψ1 = 0.86 Desired Cos ψ2 = 0.92 Voltage V :397 V p=√3 * 397 * 248 * 0.86 * 103 P = 146.6 KW Qc= P. (tanψ actual - tanψ desired) = 146.6(0.59 - 0.42) = 24.9 KVAR
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HOW TO FIND THE RELATIVE REPATABILITY & RELATIVE REVERSABILITY OF LOAD CELL

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Load Cell

A load cell is a transducer that is used to convert a force into electrical signal. A load cell usually consists of four strain gauges in a Wheatstone’s’ bridge configuration on an elastic element.


Relative Repeatability=((Fmax-Fmin)/Favg)*100


Relative reversibility =((F-F')/F(avg))*100

Where F:applied incremental force,

F': applied decremental force,

 Arithmetic Mean of indicated force

                 

                                   

Applied force kN


Indicated Deflection

Test 1

Test 2

Test 3

0.4

0.41

0.41    

0.41

0.8

0.82

0.82

0.82

1.6

1.62

1.62

1.62

4.0

4.03

4.02

4.02

8.0

8.05

8.05

8.06

12.0

12.07

12.05

12.05

16.0

16.09

16.09

16.08

20.0

20.14

20.14

20.14

From the above table take one reading.

Applied Force = 12 kN

Test 1 = 12.07

Test 2 = 12.05

Test 3 = 12.05

Mean Value = 12.0557


Relative Repeatability=((Fmax-Fmin)/Favg)*100

                            Fmax  = 12.07

                            Fmin  = 12.05
                            
                            F avg = 12.0557


             Relative Repeatability =(( 12.07 - 12.05 )/ 12.0557)*100

                                                 = (0.02/12.0557)*100
                                                 =0.1849

Relative reversibility =((F-F')/F(avg))*100
            
                                        
                                   =((12.07 - 12.05)/12.0557)*100

                                   =0.1658

                                              



                                                        

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